Text A. Pathology of the Form and Structure of the Teeth
Both systemic and local conditions may affect the form and structure of the developing teeth. In some instances only the gross appearance of the tooth is affected, the structure remaining normal; in others the structure itself is changed, or both the form and the structure may be involved.
Abnormalities of anatomical form and histological structure include multiple teeth, hyperplasia or overdevelopment, and hypoplasia or underdevelopment of the entire tooth, and hypoplasia of a part of the tooth, the crown or root. Dysplasia of the dental structures includes color changes, hypoplastic defects, and syphilitic stigmas which result from traumatic injury or infection of the developing teeth. The deciduous teeth which develop in utero are not as frequently affected as are the permanent ones. However, hereditary defects, congenitally transmitted diseases, malnutrition and diseases affecting the mother during gestation may have their effects on the deciduous teeth.
Multiple Teeth. Multiple teeth form in a variety of ways. We may distinguish germination, fusion, concrescence, and dens in dente.
Hyperplasia of the Teeth. Overdevelopment or gigantism of the teeth is called megadontism. It affects all the teeth in the arch equally and usually proportional to the development of the skeleton.
Hypoplasia of the Teeth. Hypoplasia is the reverse of hyperplasia and results in small dwarfed teeth. When the entire dentition is affected we speak of microdontism.
Dysplasia of the Teeth. Dysplasia is the result of development disturbances that may affect both the deciduous and permanent dentitions. It is not easy to classify dystrophy of the teeth. An etiologic classification cannot be carried through consistently as the knowledge of the effects on the tooth development of many of the diseases that occur during childhood is still more or less beclouded. Sometimes the disturbance is not visible until years later when the tooth erupts which makes it difficult to evaluate the cause and the effect. As a matter of fact, the teeth may be affected during gestation as well as postnatally, and a study of the mothers history as well as that of a child is necessary, therefore to detect a relation between a dental dystrophy and somatic disease.
NOTES
1. in utero
2. what is spoken of
3. as a matter of fact
VII. Give the explanation of the following terms of Greek and Latin origin in English:
abnormality, hyperplasia, hypoplasia, malnutrition, gestation, microdontism, postnatally
VIII. Answer the questions.
1. What may affect the form and structure of the developing teeth?
2. What do abnormalities of anatomical form and histological structure of the teeth include?
3. What can result in dysplasia of the dental structures?
4. What may have effects on the deciduous teeth?
5. What is germination?
6. What is fusion?
7. What is concrescence?
8. What are dens in dente?
9. What are the other terms for hyperplasia?
10. What does hypoplasia result in?
IX. Translate the sentences into English.
1. .
2. .
3. .
4. , .
5. .
6. .
7. .
